In the early years, Ready Set Rocket, a digital branding agency, hired a junior designer in its New York office. During his time with the company, the man was a valuable employee. But eventually, he decided to move back to San Francisco to be near his family.

“Since we keep an open-door policy with past employees -- whether that be inviting them to networking and agency events, or offering personal and professional support -- we retained a relationship,” founder Aaron Harvey said via email.

Luckily, three years later, the employee's skill set had advanced. He was the perfect fit for Ready Set Rocket's new needs, so the company hired him back as a senior product designer.

Ready Set Rocket isn’t the only organization looking to hire former employees. In fact, a January CareerBuilder survey of 888 hiring and HR managers found that 39 percent planned to hire former employees in 2018.

This makes sense. For years, companies have been facing a talent shortage. Unable to find qualified candidates who mesh with the company, leaders are turning to former -- or "boomerang" -- employees. These people have proven that they can succeed in the organization. So, as long as they left on good terms, why not ask them back?

The trick is finding a way to re-engage these people. And that requires employers having a great professional relationship with employees after they leave. Here are the attitudes and moves that can help make that happen:

Leaving isn’t personal. The employee's career is.

Many employers feel betrayed when a great employee decides to leave. Leaders have worked hard to create a fabulous work environment, and then people abandon it. But this is the wrong way to look at the situation.

At Kronos, a Lowell, Mass.-based workforce management and HCM cloud software company, the focus is always on the individual and its needs. According to chief people officer Dave Almeda, the company views employees’ careers as something the individual owns, not the company. It’s the organization’s job to focus on creating an engaging environment that values people.

“Kronos believes that a career is a deeply personal thing,” Almeda said wrote via email. “If a Kronite has an opportunity that’s too great to pass up for themselves or their family, they should take it. If there’s a former high-performing Kronite looking to come back, it would be silly to shut the door on them, and certainly not in the best interest of our customers.”

Instead of feeling wronged when a great employee leaves, be happy for this person. When a leader has created a great working environment, he or she should be confident that, if the circumstances are right, the employee will come back.

Keep tabs on where they've gone. (Professionally) stalk them.

When an employee succeeds, leaders can claim some credit. After all, good employers help to develop employees. And, because of this, they should take an interest in where employees go next. Following these people's careers might start off based on curiosity. But to get those people to come back, a leader also needs to be supportive.

This is why leaders should keep in contact with their former employees on professional sites like LinkedIn. Congratulate them on their latest accomplishments. Share interesting articles with them. Make lunch plans if you're attending the same conference.

By keeping tabs on former employees, leaders can see how they’re developing. The person’s career might even take an unexpected turn. By seeing what new experiences or skills the former employee has obtained, a leader can find a different position for him or her. That may lay the groundwork for a new job offer and a "boomerang back."

Give them forward steps.

Think about boomeranging from an employee’s perspective. For many people, returning to an old employer is a step backward. They left for bigger things and feel that returning is a sign of failure. This is why it’s important to show how coming back takes their career to the next level.

For instance, PR firm Walker Sands Communications was opening a new office and needed to find employees who could get up to speed quickly. Luckily, a former employee was living in the new city. To get her back, the company needed to provide a perspective on her future.

“It was crucial that our offer justified leaving her new employer so soon and provided opportunities for career advancement beyond what was possible in her previous position,” Seattle-based account director Annie Gudorf said by email. “Of course, compensation and benefits were adjusted to exceed her new employer's, but the conversation really centered on the unique learning and development opportunities our role provided.”

Offer enticing benefits to help them transition back.

There are many reasons a person leaves a company. For example, an employee may leave to start a family. Or go back to school. Or even travel the world for a while.

When these types of employees are ready to come back to work, they need extra support. Offer them the right types of benefits to make this transition easier. Provide perks like relocation stipends, tuition reimbursement and child care.